An imaginary, or social imaginary is the set of values, institutions, laws, and symbols common to a particular social group and the corresponding society. Jacques Lacan introduced the term in 1936 and continued to use it throughout his work as one of the three orders in his psychoanalytic theory. The imaginary as a lacanian term entails connotations of illusion, seduction and fascination but is by no means unnecessary or inconsequential (as something that is illusory). It defines the dual relationship between the ego and the specular image. In 1975, Cornelius Castoriadis used the term in his book The Imaginary Institution of Society. In 1995 "Technoscientific Imaginaries" was used as the title of a volume ethnographically exploring contemporary science and technology. A collection of encounters in the technosciences by a collective of anthropologists and others, edited by George Marcus, the goal was to find strategic sites of change in contemporary worlds that no longer fit traditional ideas and pedagogies and that are best explored through a collaborative effort between technoscientists and social scientists. While the Lacanian imaginary is only indirectly invoked, the interplay between emotion and reason, desire, the symbolic order, and the real are repeatedly probed. Crucial to the technical side of these imaginaries are the visual, statistical, and other representational modes of imaging that have both facilitated scientific developments and sometimes misdirected a sense of objectivity and certitude.

While not constituting an established reality, the social imaginary is nevertheless an institution inasmuch as it represents the system of meanings that govern a given social structure. These imaginaries are to be understood as historical constructs defined by the interactions of subjects in society. In that sense, the imaginary is not necessarily "real" as it is an imagined concept contingent on the imagination of a particular social subject. Nevertheless, there remains some debate among those who use the term (or its associated terms, such as imaginaire, as to the ontological status of the Imaginary. Some, such as Henry Corbin, understand the imaginary to be quite real indeed, while others ascribe to it only a social or imagined reality.

Canadian philosopher Charles Taylor expands on the concept of Western imaginaries in his book "Modern Social Imaginaries" (2004). He attempts to describe modernity and modern morality as a system of mutually beneficial spheres, in particular the public sphere of Habermas, market economy, and the self-government of citizens within a society.